Several folks will probably say to do it yourself after the lift is installed. There are a few different ways, but I think the most common is to use a tape measure, pick a spot on the front and rear of each tire. You will need to mark the spot somehow, so you can get as close as possible each time. Take a measurement at the front of the tires and then at the rear of the tires. They should be about equal. Turn your tie-rod to to get the tires to move in the direction you need. Some folks may say that you will want the front tire measurement about 1/4 inch smaller than the rear measurement.
When done, tighten your tierod adj bolts....
Now I may have missed a step or some important stuff. I am sure someone will correct me, but this will get you by.
Good luck!